The who, what, where and why of letting it burn

A dusting of new snow here in Paonia, Colo., HCN’s home base, is making it difficult to imagine the fast-approaching fire season. But it won't be long before the walkie-talkies crackle to life and giant tanker aircraft are dusting the mountains with red fire-suppressant.

Which fires will the Forest Service fight? This spring, the agency re-instated its so-called "let burn" policy, meaning it will allow some fires -- or parts of fires -- to run their natural course. Agency jargon can make it difficult to understand which fires these are. But, as I found out from talking to Tim Sexton, a researcher at the National Interagency Fire Center in Boise, Idaho, it's not impossible to get a basic understanding of the criteria that the Forest Service will use this summer to decide how to fight fire. Here they are, in order of priority.

1) Was the fire human-caused?

If so, the Forest Service will work to immediately put it out. The agency doesn't want to encourage folks to light fires willy-nilly, thinking they're helping the forest. And there are legal liabilities associated with letting a human-caused fire burn. This includes any prescribed burns that jump their lines. Interestingly, the Park Service may allow human-ignited fires to burn because in some of the smaller park units, according to Sexton, "they feel that they have a deficit of fire on the landscape, and they want to take advantage of any start."

2) Where is the fire?

Certain areas in forests, primarily in wilderness areas, are identified as places where natural fire can safely play a beneficial role in maintaining healthy ecosystems. Fire helps check the spread of insects and disease, and some ecosystems, like ponderosa forest, are adapted to periodic low-intensity burns that clean out the understory. Each individual National Forest decides where fire could serve a restoration purpose, and those areas are identified in that forest's management plan.

3) When is the fire?

Even if a fire is ignited by lighting in wilderness, it may be a candidate for suppression if it would burn habitat, such as a nesting area, that's critical during a certain time of the year. Timing during the fire season also factors into other criteria, like risk: a fire started early in the fire season has a greater chance of speading and becoming a danger.

4) What do the locals think?

In 2012, the Forest Service changed its fire policies to emphasize pre-season planning with other agencies, local firefighters and landowners. The agency may have identified an area as being suitable for restoration fire, but if the owner of a private inholding is opposed, for example, that's a significant factor in the agency's decision.

5) What are the risks?

This includes danger to public safety and private property, plus risks to fire fighters. Challenging terrain, like steep, rocky slopes and dense forests, could make the fire difficult to manage if it grows.

6) What's the long-term benefit?

This is basically a cumulative weighing of restoration benefits versus potential risks. If it looks like the fire could be allowed to run a natural course for the remainder of the fire season without getting out of hand, it's a candidate for "let burn." But if it looks like it could blow up and get expensive to fight, or move into areas that endanger safety or property, it may be put out.

7) What's the plan?

Prior to 2009, the Forest Service would decide shortly after a fire started whether to suppress it or manage it for restoration, and the agency was expected to stick to its plan. Changes to federal fire policy in 2009 allow the agency more discretion throughout the whole process, meaning fire-line officials can change their minds as fire conditions change.

Even when the Forest Service is “letting it burn,” the term is a little misleading. "None of these fires are just 'let burn,'" says Sexton. "Any time we make a decision to allow a wildfire help us achieve a restoration objective, that fire is carefully managed from ignition until it's out."